Hand carried power tool



De 16, 1952 B. B. BuTz HAND CARRIED PowRR Toor.

Filed Jan. 17, 1949 Patented Dec. 16, l1952 UNITED STATES PATENT oFElcE HAND CARRIED POWER TOOL Bert B. Butz, St. Louis, Mo., assigner to Tri-Saw Corporation, St. Louis, Mo., arcorporation ofl Missouri Application January 17, 1949, Serial No. '71,351

This invention relates to a hand carried power tool ofthe reciprocating type and pertains more particularly to the structure thereof for simplifying the assembly and dissemblyof the tool, this being the primary object of the invention.

Another object of the invention is to provide a casing of an improved structure for retained seating of the operating parts of the tool, and a cover therefor having seating cooperation with certain of the operating parts.

A further object is to provide the operating parts of the tool of a character to be self-seating with respect to their assembly in the casing of the tool.

A still further object is to provide the casing and its cover of a construction t-o form a holder for the tool, which can be ttingly held by the hand of the operator for guiding and directing the tool.

Still another object is to provide the holder with a longitudinal nat-sided tool chuck, which is reciprocally encased in surrounding guiding Walls.

Another still further object is to provide the holder with an improved work-rest at one end and a guard at its opposite end.

It is still another object of the invention to provide a tool chuck of a character to downwardlyl incline the tool such as a saw blade at a desired angle so that the blade will clear itself of sawdust during reciprocation thereof.

With the foregoing and other objects in view which will appear as the description proceeds, my invention resides in the combination and arrangements of parts and in the details of construction hereinafter described and claimed, it being understood that changes may be made within the scope of what is claimed, without departing from the spirit and intents of the invention.

An embodiment of the invention is illustrated in the accompanying drawing wherein:

Figure 1 is a longitudinal vertical sectional ele- Vati-on taken through this improved hand carried.

power tool.

Figure 2 is a horizontal sectional elevation taken approximately on the line 2-2 of Fig. 1.

Figure 3 is a transverse vertical sectional elevation taken approximately yon the line 3--3 of Fig; 1. Y

Figure 4 is an end elevation taken in the direction of the arrow 4 in Fig. 1.

Figure 5 is a transverse vertical sectional elevation taken approximately on the line 5-5 of Fig. 1L

i. Figure 6 is al transverse verticalsectional ele- 8 Claims. (Cl. 143-68) vation taken approximately on the line 6&6 of

Fig. 1.

Figure 7 is an enlarged transverse sectional elevation taken approximately on the line 1-1 of Fig. 1. y

Figure 8 is a side elevation of the tool with an end portion thereof broken away.

Referring by numerals to the accompanying drawing, 9 designates a holderfor encasing the operating parts for reciprocating the tool or hack-saw blade I0, projected from the chuck II formed on one end oa cross-head I2.

The holder 3 comprises a longitudinally eX- tending casing I3 and a cover I4 therefor, secured thereto by cap screws I5, saidcasing having a longitudinal open top guideway IB formed therein and having finished vertical side walls I1 and a finished bottom wall IB, for the reception of the cross-head I2 which Vis rectangular in cross section for snug guiding tness with the walls of the guideway IB and kwith the top side. I 9 ofthe cross-head in ush horizontal alinement with the finished surfaces 20 on each side of the guideway I6 of the casing I3. g 1 The guideway I6 extends to the front end 2l of the casing I3, and rearwardly of the inner end of the guideway, a well or depression 22 is formed in the casing I3 in which a longitudinally extending connecting rod 23 and a flywheel 24 are disposed, said rod 23 having a bearing 25 at one end for engagement on a dowel pin 26, vertically extended from the end portion 21 of the cross-head I2 and a bearing 28 at its other end for engagement on a dowel pin 29 which is vertically extended from the flywheel 24 adjacent its perimeter.

The end portion 21 of the cross-head I2 is formed by cutting away that part of the material thereabove, so that the bottom surface of the end portion will remain flush with that of the crosshead and in continued horizontal alinement with. the bottom wall I8 of the guideway IB is a longitudinally extending bearing surface 30 onl the top side of a ridge 3 I, for sliding cooperation with the bottom side of the cross-head, said ridge being in the well 22 and extending to vand joining a circular wall 32 at the rear endof the well. The wall 32 is disposed at the rear end of the well 22 and has an annular seat 33 formed therein for the support of a bearing 34,`secured therein by a yset-screw 35, said bearing supporting the upper end of a shaft 36, vertically depending-in a well 31 and being seated at its lower end in a bearing 38 in a part of the casing I3 at the bottom of the well 31.

' Fixedly secured tothe upper end of theshaft,

36 above the bearing 34 is the flywheel 24, and securely fixed to said shaft beneath said bearing by a set-screw 39 is a miter gear 4I) meshing with a miter gear 4I, securely xed to an end of a horizontal shaft 42 by a set-screw 43, said shaft being mounted in an Oilite sleeve 44, supported in abearing745 Whichrisiheld fixed by a set-screw 4B in the` cylindrical portion 4l' of the casing I3 at the rear end thereof.

A thrust .bearing 48 is mounted on the shaft 42 and is seated in a counter-bore 49 formed in the rear end of the bearing 45, said bearing 48being held in position by a collar. 5B on the extending end 5I of the shaft 42;

The cover I4 for the casing I 3/ ofAV which the holder 9 is comprised, is provided with nished meeting edges for cooperation' withthef-fi'nished meeting edges of the casing so that a seal-tight joint is maintained therebetween, when the cover and. casingvaresecured by' the cap screws I5, and in addition; the coverhasa" centrally disposed longitudinally depending ridge 52 having a nished bottom' surface' 53' for bearing clearance with thetopsides I9 and`23 of the cross-head I2 and the connecting rod 23, respectively.

The tool chuck- I I which is formed von the outer extending end of the lcross-head I2 opposite to the end-21 to which onepend of the'connecting rod 23`is"conn'ected,'.isr provided by milling a slotted recess 54: inv the' bottom' side of the extending end'of thecross-head' to" provide an inverted bottom 55n therein whichis'inclin'ed'downwardly and forwardlyv a'sshown` in' Fig. 1, and in'completing the making of the, chuck,` a' .block5 havinga rec'essfETIwithabottom end 58 :paralleling the bottom 55` oi'` the recess. 54,3is brazed or'welded tothe crossfhead onth'emeeting line59,A shown iniFigs. l and 7', ,therebyprovi'ding anY elongated verticallopening 64 'for thereceptionof the shank 6`I` of. thesaw blade' Ill, said blade being secured ingthe.v chuck with `the. shank endinY abutment againstLthe pinl2fb`y, a, set-screw 63 of. theAllen type which is threadingly secured in aside wall of the chuck,

The front.endlofitliecoverv Ill-.is bifurcated for providing, aH pair ofl forwardly and"V downwardly extending. portions 164', theinner ends voffsaid portionsabutting the front end'-2I ofthe casing I3', formingprotectingsides forthe chuck I I, one

ofsaidportionsl having an opening B5 for the insertion `of Ta wrenching tool for engagement with thesetfscrewy 63;

Acombinedlguard` andworkerest 6,6 having a pair. of.. vertically. extending ,branches 6-'I secured to the front ends of respective portions 64 by screws 68, forms a part of this improved. tool, said. branches. being rearwardly bent. at their lower ends .and extending tothe-front end 2l of thecasing I3, and yarejoinedwith each .other at 69; there adjacent, for providingu an'- upwardly extendingportion'I0-having a-recess 'II for over engaging a dependingrshoulder I2 formed-onzthe frontend 2|- offthecasing" I3(Fig: 5), said por` tion'v 'I0 'overlapping the inner ends ofthe pair ofportions64-of the cover I4 (Figs. land 8^);

Obviously; theA combined guardV and .work-rest 66"-iscarried'by the'cover I4; and'thebranches SIbein'g spaced from each other, strad'dle the saw blade I0',.and" the said: branches where they lare rearwardlyl'b'ent; form lworkeresting4 shoulders 'f3 forth'ei t'colforA engagement .against they structure worked'upon'asindicated at'Hl` in Fig. 8.

In 1 readiness? for'assem'bling the tool, therelated parts of respective shafts. 36vr and 42, are flr'st'l mounte di andlsecured thereon, thefsha'fti` 3 S ,4 with its mounted parts, gear 4I), bearing 34 and flywheel 24, being lowered in the well 3'! of the casing I3, until the bearing 34 comes to rest on its seat 33, and the setscrew 35 is tightened against the periphery thereof. The shaft 42 with its mounted parts, gear 4I and bearing 45 supportingthe sleeve 44 and the thrust bearing 48, is horizontally slid into.' the cylindricalv portion 4'Vof the casing i3, with the gear 4I in working mesh with the gear lill, and the set-screw 45 is tightened for xedly securing the Ybearing 45.

Thecro'ssI-hfead I2 is then seated in the guideway- I5,and the connecting rod 23 is mounted on thedowe'l pins*'2-" and 29 of the cross-head and the `ywheeljZ'flA respectively. Grease is then filled in the well22`of "the casing and the cover I4 is mounted thereoncand secured by the cap screws I5.

The'mounting and securing of the related parts on respective shafts lland 42, ready for them being insertedlas lsep'arate-unitsv in the casing i3 enhances l them" forfboth ease' and simplicity` of mounting inthe' casingv and whereby the units areA held in theirfadjusted cooperating settings by the respective set-screws 35 and 45S The mounting'of the cross-head I2'in the guide Way I5,v and the ease of connecting the rod 23 thereto arid'to the fly wheel 24,- isof maximum simplicityv and the slidng-surfacefof the ridge 52 of the cover I4, bearingagainst the top sides ofl both the cross-headiand theccnnecting rod, will'iittingly seat them-'againstslap'or looseness.

In theevent there isV requirement for removability of the operating parts, removal of the cover I4lwill provide access'to the parts I2 and 22' for lifting I them` from` their seatedl positions, and retractionofthe set-screwsv 35A and 46 will permit'removalof the-units having therespective gears 4l! and 4l. Grease filled in the well 37 may retard pulling of theunit of the' shaft 42, dueto a formedvacuum in said well, and in this event vacuumrelieff'may tbe` had'through the oil or grease ducts, 3io, which extend from the well 22- tothe bottom ofthewell "3 If A' cylindrical guard 'I'5f`is1rexnovably mounted on the reduced endl'i ofthe cylindrical portion 411 ofthe casing I3, by thecapscrew TI, said guard-having an opening "ISin its periphery and preferably in l the bottom disposed side thereof.

The branches S'Iof the work-rest 55 being separated from'each other provide for said'workrest being free'k from accumulatingr sawdust.

In preparing the tool for operation, the. desired saw 'blade i6 is selectedand` its shank 6I is inserted'in' the opening' of the chuck II in abutment with thepin 62 and with the upper andlower edges ofthe shank tting against respective inclined bottoms and- 58 of the opening ll and the set-screw 63 is tightened by a wrench in the socket of saidset-screw.

The driving end or: chuckn 'ISQ of. an electric motor Blis inserted inthe guard` l5,I and the chuck'v is gripped.v on theextending end 5I of the shaft 42 by a geared tool 8| which'is insertedfthroughthe openingl'l for meshing with the teeth 82 of the chuck for hand turning the chuck-intightening `it on theshaft end" 5I. The toolw'li` is thenreleasedfrom the'chuck l and is withdrawn through the opening "I3 of the guardfli In operation, the hand-grip portion 83" of the motor' Blfis grasped in onehandby the operator and` the other hand is= gripped aroun'd'the barrel portion 84 of the holder 9 and that portion' of the-cover I4thereabove;1 and` upon actuation of 5. the'` switch lever 85l of themotor, the shaft 42 is revolved, thereby revolving ythe vertical shaft. 36 and the fly wheel 24 by the meshing gears 4I and 40, said fly 'wheel' reciprocating the crosshead I2 by the connecting rod 23 and the saw blade l in the extending end of the cross-head or chuck I I.

The work-rest 66 and its shoulders 13 is important in carrying out certain kinds of work, and is particularly important at the beginning of the saw cutting, in that a firm saw directing grip of the tool'holder 9 can be maintained, against the structure to be worked on as exemplified at 14 in Fig. 8, and the angle of incidence given `to the saw blade, which approximates 7l degrees from a horizontal plane through the holder, provides more effective cutting in the work,"than if the blade was held in a horizontal plane with respect to the chuck Il by reason of the inclined and inward pulling tendency given to the blade with respect to the saw cutting being made by the blade, when in op- The extreme end of the end portion 21 of the cross-head I2 on its bottom side is rounded at 86 so that scraping of said end portion on the bearing surface 30 on the ridge 3| is prevented, in the event that the chuck end of the crosshead tends to cant upwardly, due to wear on the guiding walls of the cross-head.

Differing types of sawblades of differing widths and lengths can be used providing the shanks thereof are of sizes comparable with the chuck opening 60.

Obviouslyl constructional modifications of the device shown, are possible without departing from the spirit of the present invention and therefore it is to be understood that it is not necessary to limit the invention by the terms used in the foregoing description, excepting such as the state of the art may require.

What I claim is:

1. In a hand-carried power-operated tool having a casing with a pair of opposed extensions at one of its ends, a tool-receiving chuck disposed between said casing extensions, and means for imparting reciprocal motion to said chuck, the improvement comprising a work rest member having a pair of parallel branch members for disposition in opposed lateral relation with respect to the tool-receiving chuck as the same is reciprocated, said branch members being each secured on the outwardly presented face of a casing extension for projection therebeyond, said branches being each angulated at a point spacedly from said casing extensions to provide inwardly directed `portions for securement to said casing at points remote from the outwardly presented face of the casing extensions.

2. In a hand-carried power-operated saw having a casing, a cross-head disposed in said casing and projecting at one end therebeyond, and means for imparting axial reciprocal motion to said cross-head, the improvement comprising a chuck carried by said cross-head on its projecting end and having a socket the axis of which is inclined to the axis of the cross-head for maintaining a saw blade at an angle to the axis of reciprocation of said cross-head in order to provide a pulling force to said saw blade during operation.

3. In a hand-carried power-operated saw having a casing, a cross-head disposed in said casing and having one end extending therebeyond, and means for imparting axial reciprocal motion to said cross-head, the improvement comprising a chuck integrally formed on the extending end of said cross-head for movement toward and away from the casing upon operation of the cross-head, said chuck having a socket axially inclined with reference to the axis of the crosshead for receiving the shank of a saw blade to present the cutting edge thereof at an angle to the axis of reciprocation of said cross-head, andv means for removably securing the shank of said saw blade in the chuck socket.

4. In a hand-carried power-operated tool having a casing and a cover for said casing, the `improvement comprising a cross-head disposed in said casing vand extending at one end therebeyond, means for imparting axial reciprocal motion to said cross-head, said cross-head' at its projecting end being provided with a'recess having one face thereof inclined with respect to the axis of reciprocation of the cross-head, and a block member secured to the projecting end of the cross-head and being complementarily recessed to form with the cross-head recess a chuckforming socket, the axis of which is inclined to the axis of reciprocation of the cross-head, so that the shank of a tool received within the socket will be disposed at an angle to the axis of reciprocation of the cross-head.

5. In a hand-carried power-operated tool having a casing and a cover for said casing, the improvement comprising a cross-head disposed in said casing and extending at one end therebeyond, means for imparting axial reciprocal motion to said crosshead,isaid cross-head at its projecting end being provided with a recess having one face thereof inclined with respect to the axis of reciprocation of the cross-head, a block member secured to the projecting end of the cross-head and being complementarily recessed to form with the cross-head recess a chuckforming socket, the axis of which is inclined to the axis of reciprocation of the cross-head, so that the shank of a tool received within the socket will be disposed at an angle to the axis of reciprocation of the cross-head, a pin extending transversely across the socket at its interior end for abutment against the end face of the shank of the tool for limiting the reception of the same within the socket, and means for removably maintaining the tool therein.

6. In a hand-carried power-operated tool having a casing with a pair of opposed extensions at Lone of its ends, a tool-receiving chuck disposed between said casing extensions, and means for imparting reciprocal motion to said chuck, the improvement comprising a pair of parallel branch members for disposition in opposed lateral relation with respect to the tool-receiving chuck as the same is reciprocated, said branch members being each secured in covering relation on the outwardly presented face of a casing extension for projection in one direction therebeyond, said branch members being each angulated at a point spacedly from said casing extensions to determine the outer limits of projection and providing return portions directed inwardly toward the casing, said return portions being bent at their ends for securement to the casing at points remote from the outwardly presented faces of the casing extensions.

7. Ina hand-carried power-operated tool having a, casing with a pair of opposed extensions at one of its ends, a tool-receiving chuck disposed between said casing extensions, and means for imparting reciprocal motion to said chuck,

A 7' thea improvement comprising a; pant; ofiv parallel branclrmembers for'dispositioniiniopposedlateralrelation with respect 'to thegtool-receivingchuck as:tlrersan'i'efis reciprocated; said bran-ch mem bersbeing' each' secured in covering relation `on the i outwardly"presenteoli facef'of a casing Vextension' for projection in' one direction :therebeyond within'a plane parallel to theplane of" the -out- War-olly presented" faces ofthe casing extensions, said branch membersbeing Veach angulatedat a point spacedly from said casing extensions lto determine-the outerrlimits of projection and providing return portions directed inwardly' toward the casing, `said return-portions being bentY at their endsfoizsecurement to: the casing at pointsre` mote `from' the outwardly presentedy faces of the casinggextensions.

8. In a, handfoarried:powenoperated tool havingacasing and a cover forsaid'casing, the;im

prox/'ementl comprising a cross-head disposed in said casing and disposed at fone end therebeyond,

means for imparting axial reciprocal motionv to SaidCrOSS-head', said" crossfheadat its project` ingendbeing provided withv av recess, the aXis of` Whichiisinclined With respect to the vaxis. of recip- 25 tion of thel crossehead,V detentmeans extendingn transversely .across thefrecess` atits-:inner endto- BER-T B. BUTZ.

REFERENCES' CITED The following references-are of record in the le of this patent:l

UNITED STATES PATENTS Number Name Date 30,475` Griffith; Oct. 23, 1860 178,821Y Westman June 13, 1876 802,290 Holmes Oct.' 17, 1905l ,1,362,628 Kaunitz Dec. 21, 1920 1,793,053: Cahill et al.v Feb. 17, 1931v 1,855,371. Ungar Apr. 26, 1932 2,138,862 Johnston Dec. 6, 1938A 2,387,7612)l Redenbo Dec. 28, 1943 2,465,837 Benjamin et a1 Mar.y 25, 194:9 2,488,998 Turkowsk Nov. 22, 1949v FOREIGN PATENTS Number Country Date 208,301. Switzerland1 Apr. 16, 1940 

